The present invention relates to a guide carriage to a linear roller bearing including a guide carriage of this type, and to a method for its manufacture.
DE 20 2004 002 258 U1 makes known a linear roller bearing, in the case of which a guide carriage is supported in a longitudinally displaceable manner via two rows of rollers on a guide rail which extends in the longitudinal direction. The guide carriage encloses the guide rail in a “U” shape, one row of rollers being situated on each U-shaped leg. The rolling surfaces for the rollers are provided on a separate rolling surface part which is fixedly connected via an adhesive layer to the carrier body of the guide carriage. The rolling surface part includes a projection via which it is pressed into a corresponding recess in the carrier body with an exact fit. Suggested adhesives include Loctite 290 and Loctite 4062, i.e. cyanoacrylate adhesives.
According to DE 20 2004 002 258 U1, the combination of a press-fit connection and a bonded connection results in a particularly thin and even layer of adhesive. The stiffness of the guidance is increased as a result. Use is made, in particular, of the fact that the rolling surface part and the carrier body come to bear directly against one another via the press-fit connection, which increases the stiffness.
A further linear roller bearing is made known in DE 40 41 269 A1. In the embodiment shown in FIG. 11, a total of four endlessly circulating roller rows is provided. The rolling surfaces for the rollers are formed on four separate but essentially identical rolling surface parts. The rolling surface parts are inserted loosely in the carrier body of the guide carriage, their back side being designed in the shape of a circular arc, so that the rolling surface parts may orient themselves toward the rollers. It has been shown that the stiffness of a guide carriage of this type is only minimally less than that of a guide carriage in which the rolling surfaces for the rollers are situated directly on the carrier body. The loss of stiffness is determined primarily by the thickness of the steel inserts. They should be as thin as possible, so that the linear roller bearing has a high guide stiffness. The thickness of the steel inserts is limited at the lower end, however, since it must be ensured that the bearing forces of the rollers which act on the rolling surface parts in a linear manner are distributed across the entire back side of the rolling surface parts as evenly as possible.
The projecting design has the disadvantage that the rolling surface part must be fully machined separately from the carrier body of the guide carriage. The resultant thickness tolerance of the rolling surface part has a negative effect on the precision of guidance of the linear roller bearing. In addition, due to deviations of shape in the mating surfaces between the rolling surface part and the carrier body, it is possible for the rolling surfaces to not be exactly flat. As a result, the transfer of force to the rollers no longer takes place across their entire width, but only via certain points, which greatly reduces the service life of the linear roller bearing.